Most of the review is about the art assets, and I doubt the big ones (e.g. the trains themselves) are off-the-rack Unreal assets. An engine like Unreal 5 will cast your assets in harsh relief. Which is to say, if your game's assets look custom and look good in Unreal 5, it does indeed demonstrate effort and skill.
It's the lighting etc that provide photo realism with Unreal. Even the demo that comes with Unreal where a robot is running around cubes on a small plain looks photoreal.